OF ALIPHATIC COMPOUNDS. 37 



A still further advance in this field is the successful 

 substitution of iodine and of nitro-groups by elec- 

 trolysis. On electrolyzing propionic acid and potas- 

 ium iodide in aqueous solution fi-iodo-propionic acid 

 was formed, due to the int i rim ill ill fgPjmtliii 1 1 of 



succmic acid : OF THE r 



UNIVERSITY 



COOH.CH 3 .CH a .COOK + KI 



= ICH 2 .CH 2 .COOH + 2K + C0 2 . 



Nitro-ethane was probably obtained in small quan- 

 tities from sodium propionate and sodium nitrite. 



ELECTROSYNTHESES OF BROWN AND WALKER.' 



A systematic synthesis with the aid of the electric 

 current was first attained in the researches of Brown 

 and Walker. Their investigations are based partly 

 on the fact observed by Kolbe that monobasic fatty 

 acids yield hydrocarbons, and partly on the results of 

 the experiments of Guthries, 2 who found that the 

 ester group is electrolytically inactive. These facts 

 justified the hypothesis that the mono-esters of 

 dibasic acids would behave, under the action of the 

 current, like monobasic acids, i.e., carbon dioxide 



1 Lieb. Ann., 261, 107; ibid., 274, 41. 

 ? Lieb. Ann., 99, 65. 



